1. Field of the Invention
The present invention relates to ventilating devices for buildings.
2. Description of the Prior Art
Buildings are commonly heated by heating the air in the rooms and other occupied portions. As is well known, heating reduces the density of air. This causes the heated air to rise and stagnate along the ceiling of the room while cold air remains on the floor. Temperature differences of 15.degree. F to 30.degree. F may exist between the floor and the ceiling. Such stratification occurs not only in radiant heating systems, such as those employing hot water, but also with hot air systems during the intervals in which the blower is off. Because of the stratification, additional heat must be supplied to the room to make the occupied area adjacent the floor comfortable.
To overcome the thermally induced stratification and stagnation, it has been proposed to position a duct in the room extending from the ceiling to the floor. A fan coupled to the duct draws the hot air adjacent the ceiling down the duct and discharges it onto the floor, thereby reducing the temperature difference between the ceiling and floor and increasing the temperature of the occupied area adjacent the latter. See for example, U.S. Pat. No. 1,170,551 to Marty and U.S. Pat. No. 3,173,353 to Watkins which show devices of this type.
While devices of this type shown in the aforesaid patents increase the comfort in the room, it is readily apparent that little consideration has been directed to their efficiencies. Given the present high cost of energy, such prior art devices would well consume more energy than might be saved through the more uniform heating of the room.